Resistance-grid.



H. 'J. WIEGAND. RESISTANCE GRID. APPLIOATION YILE'D mute, i910, RENEWED FEB. a, 1913.

be hereinafter disclosed.

UNITED STATES nanny r. wrnannn, or MILWAUKEE, WISCONSIN. j

Application filed June 6, 1910, Serial No. 565,231. Renewed February 3, 1913.

To (4 whom 2'15 may concern:

Be it known thatI, HENRY J. WIEGAND, a citizenjof the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented newand useful Improvements in Resistance-Grids, of which the following is a full, clear, concise, and exact description, reference being liad to the accompanying drawing, forming a part of this specification.

My invention relates to improvements in the construction of resistance units, and more particularly to that-class of resistance units commonly known as grid resistance. L

The principal object of my invention is to provide simple and eflicient means for maintaining the various convolutions of the resistance grid in alinement, and at the same time effectually reinforce and strengthen the grid in a substantial manner.

Various other objects and advantages will In order to more fully and clearly set forth the characteristic features of my invention, I shall describe the same, reference being had to the drawing which illustrates certain embodiments thereof, that I have worked outin practice. It should be understood, however, that my invention is not limited to the the drawing.

In the drawing Figure l is a side elevation of the rid, Fig. 2 is an end view there of, Fig. 3 1s a-bottom view of Fig. l and 1 o Fig.4; 1s a fragmental perspective View of a modification of Fig. 1.

The resistance proper consists of a plurality of convolutions 5, composed of any suitable resistance material, the more common beingcast iron or any alloy thereof.

-' On the end convolutions of the grid are 10- cated the terminals 6 in the form of notched lugs. The extremities '7 of the convolutions, as illustrated are alternately offset in opposite directions or staggered, thereby forming a series of shoulders 8 in alinement throughout the width of the grid. Interposed between the extremities 7 and adapted to abut against the shoulders 8 of the grid are the reinforcing members 9.

v The reinforcing members'9 are preferably formed of some rigid and heat resisting material, such as fiber or transite, or anyinsulatmg element possesslng the necessary Specification of Letters Patent.

'13 substantially circular in cross section,

specific forms illustrated in mama QFFICE.

RESISTANCE-GRID.

Patented Sept. 2, 1913.

Serial. No. 746,041.

illustrated, pass through the slots 11 adja-.

cent to the closed ends of the convolutions. 0 It is, therefore, unnecessary to provide any special apertures inthe grid, with the can cepti'on of the inactive ends 12 which are shown as having rivets passing through them. In my improved construction, when the members of the rid are assembled and secured in place, the'structure becomes practically. unitary, thereby forming a grid of great strength and at the same time elimi nating the liability of short-circuiting some of the convolutions, which is apt to occur where insulated metal is used for reinforc ing the grid.

The modified structure, disclosed in Fig. 4, is practically the same as that disclosed in Fi 1, with the exception, that the rectangu ar reinforcing members 9 in Fig. 1,' are replaced by insulating rods or members and servingthe same purpose. Where cylindrical reinforcing members are used, I prefer .to provide the convolutions of, the grid with curved extremities 14, the same being staggered in a similar manner-to-that. described in connection withFigs. 1, 2 and 3. However, the grid and the reinforcing members might assume various different forms without departing from the scope ofmy present invention and I, therefore, do

not wish to ,limit myself to the specific structures shown. I

Having thus described my invention what I wish to claim and secure by Letters Patent is: 1. A resistance grid provided with an insulating reinforcing member and a device passing through portions of the grid and said reinforcing member to firmly secure said reinforcing member in place.

2. A resistance grid provided with offset portions forming shou ders, a reinforcing member 'abuttingsaid shoulders and a de-' vice passing through one ofthe slots insaid grid to hold said reinforcing member against displacement from said ,shoulders and against longitudinal slippage.

3. A resistance grid provided at the ex tremities of its 'convolutions with staggered offset portions providing shou1ders,'a rein- 11a ioo forcing member arranged between said staggered offset portions and resting upon said shoulders and a device passing through one of the slots in said grid to hold said reinforcing member against displacementfrom said shoulders and against longitudi= nal displacement.

nesses.

HENRY J. \VIEGANI). Witnesses:

Row. J. MEAD, M. R. F ENNO. 

